Medical tube article

ABSTRACT

The present invention relates to a medical tube article comprising a polymer mixture of a thermoplastic or thermocuring polymer base material and an amphiphilic block copolymer.

PRIORITY CLAIM

This is a U.S. national stage of application No. PCT/EP2010/066459,filed on Oct. 29, 2010. Priority is claimed on the followingapplication: EP Application No.: 09174578.6 filed on Oct. 30, 2009, thecontent of which is herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a medical hollow tube articlecomprising a polymer mixture.

BACKGROUND ART

U.S. Pat. No. 5,084,315 discloses an article which becomes lubriciouswhen wet, and which comprises a base polymer and a coating compositionthereon. When using medical articles, for instance when inserting onearticle into another, scraping of the article surface might occur. Thiscoated article has the drawback that it is possible to remove thecoating from the surface of the article during such scraping of thesurface, which causes the scraped area to be less lubricious.

Furthermore, when using a medical article, such as a tube in humanorifices, some of the coating will always be left inside the person,which can be harmful and thus unacceptable.

SUMMARY OF THE INVENTION

It is an object of the present invention to wholly or partly overcomethe above disadvantages and drawbacks of the prior art. Morespecifically, it is an object to provide an improved medical articlewhich maintains a low friction property even when a surface is scraped.In this way, the lubricious properties are maintained throughout theentire surface of the article.

An additional object is to provide a product easy to manufacture whilemaintaining the mechanical properties of the product.

The above object, together with numerous other objects, advantages, andfeatures, which will become evident from the below description, areaccomplished by a solution in accordance with the present invention by amedical tube article moulded or extruded from a polymer mixturecomprising a first and a second polymer, the first polymer being athermoplastic or thermo-curing polymer and the second polymer being anamphiphilic block copolymer possessing both hydrophilic and lipophilicproperties.

In one embodiment the amphiphilic block copolymer may be a hydrocarbonchain block of the formula CH3CH2(CH2CH2)_(a) where “a” is 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25, and a B-block,said B-block being hydrophilic.

Thus, a medical article is provided, comprising a thermoplastic polymeras a basis material and an amphiphilic block copolymer possessing bothhydrophilic and lipophilic properties and comprising a main block beinghydrophobic and another block being hydrophilic. The first polymer actsas a basis material and provides excellent mechanical properties, andsince the hydrophilic block of the amphiphilic block copolymer seekstowards the surface of the article due to its incompatibility with thebasis polymer, the friction efficiency of the surface is reduced. Thehydrocarbon chain and the lipophilic and hydrophobic block of theamphiphilic block copolymer ensure that the hydrophilic part is securedto the basis material below and to the basis material as such. In thisway, it is obtained that the properties of the surface remain intactregardless of which mechanical force the surface is exposed to, such asintentional scraping of the article surface.

The lipophilic property of the amphiphilic block copolymer ensures thatthe block copolymer is mixed with the first polymer and thus that theblock copolymer is securely fastened to the first polymer. Thehydrophobic block of the amphiphilic block copolymer is moreovercompatible with hydrophobic parts of the first polymer acting as thebasis polymer.

In a polymer mixture with a hydrophobic basis polymer, such aspolyolefin, the hydrophilic part of the amphiphilic block copolymer willdiffuse to the surface due to incompatibility with the hydrophobic firstpolymer.

Furthermore, it is obtained that the medical article can be sufficientlywetted just by wiping the surface with a wet tissue, since thehydrophilic part of the amphiphilic block copolymer diffuses to thesurface forming a very thin layer, which thin layer requires less waterthan a thicker coating layer.

By mixing the first polymer with an amphiphilic block copolymer, anarticle having an inherent lubricious property is obtained, andfurthermore, the product is easily manufactured just by moulding orextruding the article and thus, no subsequent coating process is needed,which saves manufacturing costs and time.

In one embodiment, the thermoplastic first polymer may be selected fromthe group of: Polyolefin, Polyvinylchloride (PVC), polyurethane (PUR),Polyolefin, Styrene-butadiene copolymer (SBC),Styrene-ethylene-butylene-styrene copolymer (SEBS) and thermoplasticelastomers, or combinations thereof.

In another embodiment, the B-block may be a hydrophilic oligomer, i.e. ahomo- or co-oligomer, consisting of between 2 and 10 monomer unitsderived from monomers selected from the group of: ethylene oxide,propylene oxide, ethylene glycol, propylene glycol, epichlorhydrin,acrylic acid, methacrylic acid, ethylene imine, caprolactone, vinylalcohol and vinyl acetate.

Furthermore, the amphiphilic block copolymer may be either Irgasurf™,Aquazol™ or Unithox™.

In addition, the amphiphilic block copolymer may constitute 0.1-20% byweight, preferably 0.5-15% by weight and more preferably 0.5-5% byweight of the polymer mixture.

The article may be any medical hollow tube article, such as an airwaytube, a feeding catheter, an intestinal catheter a suction catheter or aurine catheter.

Additionally, the medical article has a surface friction, and thesurface friction may be a kinetic coefficient of friction of less than0.4, preferably in the closed interval 0.2-0.1.

In addition, the polymer mixture has a concentration of B-block, and theconcentration of B-block at the surface of the article may be more than2-60 times the concentration of B-block in the centre of the polymermixture, preferably 3-50 times the concentration of B-block in thecentre of the polymer mixture.

Furthermore, the thermoplastic first polymer may be either Accurel™,Styroflex™, Styrolux™, MelifleX™ or Mediprene™, which are allhydrophobic.

Also, the thermoplastic first polymer may be Estane 58315, which is bothhydrophobic and hydrophilic.

The invention also relates to the use of a medical article as disclosedabove for insertion into human orifices, such as airways, the rectum,the vagina or the urethra.

Finally, the invention relates to a method for manufacturing a medicaltube article as disclosed above, comprising the steps of:

-   -   mixing a granulate blend of a first polymer being a        thermoplastic or thermo-curing polymer and a second polymer        being an amphiphilic copolymer, and    -   injection moulding or extrusion of the medical article.

In one embodiment of the method, the amphiphilic block copolymer maypossess both hydrophilic and lipophilic properties.

Moreover, the method may further comprise the step of melting thegranulate blend of the first polymer being the thermoplastic orthermo-curing polymer and the second polymer being the amphiphiliccopolymer and forming another granulate, each granulate being a mixtureof the first and the second polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its many advantages will be described in more detailbelow with reference to the accompanying schematic drawings, which forthe purpose of illustration show some non-limiting embodiments and inwhich

FIG. 1 shows a part of an article manufactured from a polymer mixtureaccording to the invention, which is in molten state,

FIG. 2 shows a part of an article manufactured from a polymer mixtureduring cooling,

FIG. 3 shows a first example of a medical article manufactured from amaterial according to the invention,

FIG. 4 shows a second example of a medical article where the article isan airway tube and is manufactured from a material according to theinvention,

FIG. 5 shows an apparatus for testing the friction of the surface of anarticle manufactured from a material according to the invention,

FIG. 6 shows a chart of different amounts of Irgasurf 560 HL in thebasis material, and

FIG. 7 shows a chart of different basis polymers comprising anamphiphilic block copolymer.

All the figures are highly schematic and not necessarily to scale, andthey show only those parts which are necessary in order to elucidate theinvention, other parts being omitted or merely suggested.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a sample manufactured from a polymer mixture according tothe invention, which sample is shown in its molten state. The polymermixture comprises a second polymer being an amphiphilic copolymer 2, 3which is mixed in a first polymer acting as a basis material 4. Thebasis material 4 is a thermoplastic or a thermocuring polymer. Theamphiphilic block copolymer 2, 3 is a hydrocarbon chain block of theformula CH3CH2(CH2CH2)_(a) where “a” is 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20, 21, 22, 23, 24 or 25, and a hydrophilic B-block. Thehydrophilic B-block is a hydrophilic oligomer, i.e. a homo- orco-oligomer, consisting of between 2 and 10 monomer units derived frommonomers selected from the group of ethylene oxide, propylene oxide,ethylene glycol, propylene glycol, epichlorhydrin, acrylic acid,methacrylic acid, ethylene imine, caprolactone, vinyl alcohol and vinylacetate. The thermoplastic basis material 4 may be selected from thegroup of Polyolefin, Polyvinylchloride (PVC), polyurethane (PUR),Polyolefin, Styrene-butadiene copolymer (SBC),Styrene-ethylene-butylene-styrene copolymer (SEBS) and thermoplasticelastomers, or a combination thereof. The sample is made of granulatecomprising the first polymer 4 and the second polymer being theamphiphilic block copolymer 2, 3 in a suitable mixture and is deliveredin granulate which, during a normal moulding or extrusion process, isheated and formed into the article in question.

Thus, the first and the second polymer are mixed to form one mixturecomprising both hydrophilic and lipophilic properties. Subsequently, themixture is moulded or extruded into a tube-shaped article. The firstpolymer acts as a basis material and provides excellent mechanicalproperties. The amphiphilic block copolymer possesses both hydrophilicand lipophilic properties and comprises a block which is hydrophobic andanother block which is hydrophilic. The hydrophilic block of theamphiphilic block copolymer seeks towards the surface of the article dueto its incompatibility with the basis polymer, the friction efficiencyof the surface being reduced as a result. The hydrocarbon chain and thelipophilic and hydrophobic block of the amphiphilic block copolymerensure that the hydrophilic block is secured in the basis material.

The first and the second polymer are comprised in the same compound sothat each granulate comprises both the first and the second polymerbefore moulding or extrusion of the article. Moulding or extruding thearticle from one mixture of the first and second polymer eliminates thesubsequent process of coating the article, and as the element resultingin the hydrophilic property on the surface of the article is anchoredchemically in the basis polymer it is not easily wiped off or leftinside the patient. Furthermore, if the surface for some reason shouldbe scratched, new hydrophilic parts will diffuse to the surface of thearticle in order to restore the chemical state of equilibrium whilestill anchoring the hydrophobic and lipophilic part of the amphiphilicblock copolymer in the basis material.

The lipophilic property of the amphiphilic block copolymer ensures thatthe block copolymer is mixed with the first polymer and thus that theblock copolymer is securely fastened to the first polymer. Furthermore,the hydrophobic part of the amphiphilic block copolymer is compatiblewith the hydrophobic parts of the first polymer and therefore acts as acompatibiliser both when mixing the first and the second polymer inorder to make the granulate and in the subsequent moulding or extrusionprocess.

In a hydrophobic basis polymer, such as polyolefin, SEBS-, SIS- andSBC-elastomers as a first polymer, the hydrophilic part of theamphiphilic block copolymer will diffuse to the surface due toincompatibility with the hydrophobic first polymer.

A further advantage is that the medical article can be sufficientlywetted just by wiping the surface with a wet tissue, or by high humidityor moisture, since the hydrophilic part of the amphiphilic blockcopolymer diffuses to the surface forming a very thin layer, which thinlayer requires less water than a thicker coating layer.

FIG. 2 shows how the material in the polymer reacts during cooling asthe amphiphilic block copolymer 2, 3 places itself in the cooledmaterial in such a way that the hydrophilic B-block seeks towards thesurface, and the carbon chain block ensures that the B-block is retainedin the basis material 4. The basis material 4 could be eitherPolyolefin, Polyvinylchloride (PVC), polyurethane (PUR), Polyolefin,Styrene-butadiene copolymer (SBC), thermoplastic elastomers orStyrene-ethylene-butylene-styrene copolymer (SEBS). In this way, thesurface will not be able to change its mechanical properties, such asits lubricious property, when scraped, as a new state of equilibriumwill be created at the surface in that the hydrophilic B-block seekstowards the surface. Compared to a coated surface which is scraped andlooses part of its coating during the scraping process, an articlemanufactured from a material according to the invention does not changeits mechanical properties as the hydrocarbon chain ensures that theamphiphilic block copolymer 2, 3 is safely secured to the base material4.

By mixing the basis material 4 with an amphiphilic block copolymer, thearticle has both excellent mechanical properties and an inherentlubricious property since the hydrophilic block seeks towards thesurface of the article due to its affinity to liquid. The hydrocarbonchain of amphiphilic block copolymer 2, 3 ensures that the hydrophilicpart is secured in the base material 4. In this way, it is obtained thatthe properties of the surface remain intact regardless of whichmechanical acts the surface is exposed to, such as intentional scrapingof the article surface.

Furthermore, by mixing the base material 4 with an amphiphilic blockcopolymer 2, 3 so that the article has an inherent lubricious property,no subsequent coating process is needed, which saves manufacturing costsand time.

The amphiphilic block copolymer 2, 3 could be either Irgasurf™ orUnithox™, which are both commercially available copolymers. The weightof the amphiphilic block copolymer 2, 3 compared to the weight of theentire polymer mixture is preferably between 0.1%-20%, more preferably0.5%-15% and even more preferably 0.5%-5%.

Due to the small amount of amphiphilic block copolymer, the mechanicalproperties of the basis material, i.e. the first polymer, are notsubstantially decreased and the mechanical properties of the medicalarticle are thus maintained.

The thermoplastic base material 4 could for instance be Accurel™,Styroflex™, Styrolux™, Mediprene™, Meliflex™ or Estane™, which are allthermoplastic polymers commercially available. The material could beused for producing a medical article such as airway tubes of differentkinds, for instance tracheal tubes or laryngeal masks, or urinecatheters.

FIG. 3 shows an example of an airway tube, such as a suction catheter 5comprising a hollow tube part 5′ which is manufactured from a materialaccording to the invention. The catheter may have openings 6 in thedistal end, and in the proximal end, the catheter may be provided with aconnector 7 for gripping the tube part 5′. It is an advantage when usingthe catheter that the surface becomes very slippery when wetted onlyslightly with body fluids before being placed in the orifice. Whereasthe coated articles known from the prior art have to be submerged inwater for up to 30 seconds in order to become sufficiently lubricous,the article of the present invention only needs to be wetted, e.g. bymeans of a wet tissue wiped over the surface, in order to become so.

Furthermore, as the product of the present invention does not containcoatings as in prior art articles, substantially no chemical elementsare left in the body. It is also an advantage that when the catheter hasbeen removed from the body, there is no coating at the surface becausethe coating often drips and causes staining when in contact with bodyfluids. This is not the case when using a catheter according to theinvention where no coating is used. An example of such a catheter isshown in WO 2008/155145 which is incorporated by reference.

FIG. 4 shows an example of an airway tube, a tracheal stoma tube, wherethe tube part 9 can also advantageously be manufactured from a mixtureaccording to the invention. This article comprises the tube part 9itself, being the outer cannula, which should be slippery when enteredinto the airways. Inside the outer cannula an inner cannula 11 isplaced, which can advantageously be manufactured from a polymer mixtureaccording to the invention. The catheter is at the proximal end fastenedto a flange 10, and a swivel locking member 12 is fastened to the outercannula. A detailed description of this device is found in WO2008/046418 which is incorporated by reference.

In another embodiment, the medical article is co-extruded having anouter layer of the mixture according to the present invention and aninner layer of a cheaper material or a material having differentproperties, such as an anti-bacterial property, e.g. comprising Ag ions.

In the example below, a method of determining the surface wearresistance compared to the surfaces of known coated articles isexplained.

EXAMPLE

Measurements of the friction on round surfaces manufactured from apolymer mixture material according to the invention, i.e. on a catheter,are conducted.

Objective:

The equipment is to be used to measure kinetic friction on roundsurfaces, for instance on tubes and rods at a predetermined distance.The test is only to be used for comparison between two articles, whichrequires the test articles to be of substantially the same dimensions.

Method:

The friction will be calculated by using the Formula: F=F_(n)*μ, where F(N) and F_(n) are recorded.

F_(n) is the weight of the round article, i.e. the tubing, including thefastening elements (called a fixture hereinafter)—F_(x)—multiplied bythe gravitation. F is recorded by pulling the fixture in a horizontaldirection.

The Test Equipment Consists of:

-   -   a vertical tensile strength test machine (load cell 10 N),    -   a horizontal plane with a replaceable surface and a pulley for        transforming the horizontal movement into a vertical movement,        and    -   a slider-fixture for mounting of two tubings/rods. The weight of        the slider-fixture can be adjusted.        Test Machine Used:

Lloyd LRX PLUS, Ser. No. 105239, Load cell 10N, Ser. No. 015511,Calibrated in June 2009.

Process:

With reference to FIG. 5, the test items 15 are mounted underneath theslider 13, and the replaceable surface is prepared. Currently, a wetwash leather is used. The slider 13 is placed on the replaceable surfaceand is made of two tubes manufactured from different materials, and thetest sequence is started. The tube is placed on a plane surface 14 onwhich the wet wash leather is arranged.

The pulling force is recorded in a graph.

By the known factors F and F_(n), the Friction coefficient iscalculated.

Recordings:

-   -   Weight of slider    -   Average force registered (1000 measure point/second within a        defined part of movement)    -   Pull speed (stationary value)    -   Surface used    -   Product tested, with available data of origins.

In table 1 the results of the experiments are listed.

The chosen material covers four samples manufactured from a materialaccording to the invention. This is to be compared to four commerciallyavailable catheters: SpeediCath™, EasiCath™, LoFric™ and LoFric Plus™.All these commercially available catheters are coated. As can be seenfrom the results, the friction F_(n) measured on round itemsmanufactured from a material according to the invention is much lowerthan the commercial catheters and is comparable with LoFric Plus™.

TABLE 1 Code LoFric Easi- Speedi- LoFric Plus F FF H HH Cath CathNelaton Nelaton Weight of 317.5 317.5 317.5 317.5 317.5 317.5 317.5317.5 317.5 317.5 slider F_(x) [grams] Wet wash 4 B 4 B 4 B 4 B 4 B 4 B4 B 4 B 4 B 4 B leather Pull 250 250 250 250 250 250 250 250 250 250velocity [mm/min] Pull 100 100 100 100 100 100 100 100 100 100 distance[mm] Basis 100% 97% 85% 100% 97% PP 85% PP — — — — material AccurelAccurel Accurel Meliflex Meliflex Meliflex XP850 XP850 XP850 M6504 M6504M6504 Amphiphilic 0% 3% 15% 0% 3% 15% — — — — block Irgasurf IrgasurfIrgasurf Irgasurf copolymer 560 HL 560 HL 560 HL 560 HL Numbers of 8 8 88 8 8 8 8 8 8 experiments Friction of 1.452 0.1656 0.1182 1.3212 0.18610.1406 0.2072 0.3760 0.2401 0.1441 coefficient μ average Standard 0.07630.0107 0.0045 0.0241 0.0296 0.0091 0.0086 0.0225 0.0086 0.0287 deviationof μ

As can be seen from the results, the coefficient of the friction isreduced by nearly a factor 10 when 3% by weight Irgasurf is mixed in thebasis material.

In FIG. 6, a chart is shown based on the measured kinetic coefficient offriction in articles of Meliflex M6504 mixed with 0.0%, 0.1%, 0.5%,1.5%, 3.0 or 15% Irgasurf 560 HL. The kinetic coefficient of friction ismeasured to 1.32 at 0.0% Irgasurf 560 HL in the basis material MeliflexM6504, to 1.17 at 0.1% Irgasurf 560 HL, to 1.14 at 0.5% Irgasurf 560 HL,to 0.15 at 1.5% Irgasurf 560 HL, to 0.15 at 3% Irgasurf 560 HL, and to0.13 at 15% Irgasurf 560 HL.

As can be seen from these results, the intended effect is obtained at1.5% Irgasurf 560 HL mixed in Meliflex M6504, since the measured kineticcoefficient of friction is substantially reduced at this concentration,i.e. from 1.15 to 0.14, while the amount of Irgasurf 560 HL added isstill very small, i.e. only 1.5%. The mechanical properties of anarticle, such as a catheter, moulded or extruded from this mixture arethus still maintained while at the same time providing the article withsufficient lubricious properties to be acceptable for a patient.

TABLE 2 Kinectic coefficient Code Material of friction F Accurel XP850(97%) and Irgasurf HL560 (3%) 0.165 H Meliflex M6504 (97%) and IrgasurfHL560 (3%) 0.186 L Estane 58315 (PUR) (97%) and Irgasurf HL560 (3%)0.155 N Mediprene 500803M (Polyolefin compound) (97%) 0.1394 andIrgasurf HL560 (3%) O Mediprene OF800M (Polyolefin compound) (97%)0.1594 and Irgasurf HL560 (3%) R Mediprene 500803M (Polyolefin compound,shore 0.2571 hardness 80) (97%) and Irgasurf HL560 (3%) S Mediprene500803M (Polyolefin compound, shore 0.2134 hardness 85) (97%) andIrgasurf HL560 (3%) T Mediprene 500803M (Polyolefin compound, shore0.1941 hardness 90) (97%) and Irgasurf HL560 (3%)

As can be seen from table 2, other thermoplastic polymers than Meliflexand Accurel can be used as the first polymer, i.e. the basis polymer. Intable 2, the kinetic coefficients of friction at various basis polymersare listed and a chart from the results can be seen in FIG. 7. Whencomparing a tube article of a basis material without any amphiphilicblock copolymer in table 1, such as a tube article of 100% AccurelXP850, with the tube articles containing an amphiphilic block copolymer,the tube articles with amphiphilic block copolymer have a substantiallylower kinetic coefficient of friction than those without amphiphilicblock copolymer. As can be seen from table 2, Mediprene and Estane havealso proven to be suitable as a first polymer in order to reduce thesurface friction of an article.

The surface of an article may refer to the outer surface and/or theinner surface of the article. Even though only the outer surface hasbeen disclosed in the above, an inner surface having a low kineticcoefficient of friction may be desirable as well, e.g. in medical tubesto be penetrated by instruments during examination of a patient.

The articles of the invention may be manufactured by extruding thearticle or by injection moulding.

Although the invention has been described in the above in connectionwith preferred embodiments of the invention, it will be evident for aperson skilled in the art that several modifications are conceivablewithout departing from the invention as defined by the following claims.

-   1. Part of an article comprising a polymer according to the    invention-   2. Part of an amphiphilic block copolymer hydrocarbon chain block-   3. The other part of the amphiphilic block copolymer, i.e. B-block-   4. Thermoplastic or thermo curing polymer being the base material-   5. Urine catheter comprising a hollow flexible tube-   5′Hollow tube part-   6. Openings-   7. Connector-   8. Airway tube (tracheal stoma tube)-   9. Outer cannula-   10. Flange for fastening the airway device-   11. Inner cannula-   12. Swivel locking member-   13. Slider-   14. Plane surface-   15. Test item

The invention claimed is:
 1. A medical tube article moulded or extrudedfrom a polymer mixture comprising a first and a second polymer: thefirst polymer being a thermoplastic or thermo-curing polymer, and thesecond polymer being an amphiphilic block copolymer possessing bothhydrophilic and lipophilic properties, wherein the amphiphilic blockcopolymer constitutes 0.5-15% by weight of the polymer mixture, andwherein a concentration of hydrophilic B-block at the surface of thearticle is more than 2-60 times a concentration of hydrophilic B-blockin the centre of the article.
 2. The medical tube article according toclaim 1, wherein said amphiphilic block copolymer is a hydrocarbon chainblock of the formula CH₃CH₂(CH₂CH₂)_(a) where “a” is 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25, and a B-block, saidB-block being hydrophilic.
 3. The medical tube article according toclaim 1, wherein the thermoplastic first polymer is selected from thegroup of: Polyolefin, Polyvinylchloride (PVC), Polyurethane (PUR),Styrene-butadiene copolymer (SBC), Styrene-ethylene-butylene-styrenecopolymer (SEBS) and thermoplastic elastomers, or combinations thereof.4. The medical tube article according to claim 2, wherein the B-block isa hydrophilic oligomer, i.e. a homo- or co-oligomer, consisting ofbetween 2 and 10 monomer units derived from monomers selected from thegroup of ethylene oxide, propylene oxide, ethylene glycol, propyleneglycol, epichlorhydrin, acrylic acid, methacrylic acid, ethylene imine,caprolactone, vinyl alcohol and vinyl acetate.
 5. The medical tubearticle according to claim 1, wherein the amphiphilic block copolymerconstitutes 0.5-5% by weight of the polymer mixture.
 6. The medical tubearticle according to claim 1, wherein the medical article is an airwaytube, a feeding catheter, an intestinal catheter, a suction catheter ora urine catheter.
 7. The medical tube article according to claim 1,wherein the medical article has a surface friction, and the surfacefriction is less than 0.4.
 8. A method of using a medical tube articlecomprising inserting the medical tube article into a human orifices, themedical tube article being moulded or extended from a polymer mixturecomprising a first and a second polymer: the first polymer being athermoplastic or thermo-curing polymer, and the second polymer being anamphiphilic block copolymer possessing both hydrophilic and lipophilicproperties, wherein the amphiphilic block copolymer constitutes 0.5-15%by weight of the polymer mixture, and wherein a concentration ofhydrophilic B-block at the surface of the article is more than 2-60times a concentration of hydrophilic B-block in the centre of thearticle.